Abstract

The knee is one of the most commonly affected joints in osteoarthritis. Unicompartmental knee replacement (UKA) was developed to address patients with this disease in only one compartment. The conventional knee arthroplasty jigs, while usually being accurate, may result in the prosthesis being inserted in an undesired alignment which may lead to poor post-operative outcomes. Common modes of failure in UKA include edge loading due to incorrect sizing or positioning, development of disease in the other compartment due to over-stuffing or over-correction and early loosening or stress fractures due to inaccurate bone cuts.

Computer navigation and robotically assisted unicompartmental knee replacement were introduced in order to improve the surgical accuracy of both the femoral and tibial bone cuts. The aim of this study was to assess accuracy and reliability of robotic assisted, unicondylar knee surgery in producing reported bony alignment.

Two hundred and twenty consecutive patients with a mean age of 64 + 11 years who underwent successful medial robotic assisted unicondylar knee surgery performed by two senior total joint arthroplasty surgeons were identified retrospectively. The mean body mass index of the cohort was 33.5 + 8 kg/m² with a minimum follow-up of 6 months (range: 6–18 months). Femoral and tibial sagittal and coronal alignments as well as the posterior slope of the tibial component were measured in the post-operative radiographs. These measurements were compared with the equivalent measurements collected during intra-operative period by the navigation to study the reliability and accuracy of femoral and tibial cuts. Radiographic evaluation was independently conducted by two observers.

There was an average difference of 2.2 to 3.6 degrees between the intra-operatively planned and post-operative radiological equivalent measurements. For the femur, mean varus/valgus angulation was 2.8 + 2.5 degrees with 83% of those measured within 5% of planned. For the tibia mean varus/valgus angulation was 2.4 + 1.9 degrees with 93% within 5% of planned resection. There was minimal inter-observer variability between radiographic measurements. There were no infections in the evaluated group at the time of radiographic examination.

Alignment for unicondylar knee arthroplasty is important for implant survival and is a more difficult procedure to instrument as it is a minimally invasive surgery. Assuming appropriate planning, robotically assisted surgery in unicondylar knee replacement will result in reliably accurate positioning of component and reduce early component failures caused by malpositioning. A mismatch between pre-planning and post-operative radiography is often caused by poor cementing technique of the prosthesis rather than incorrect bony cuts. Addressing these factors can lead to greater success and improved outcomes for patients.

Introduction

Regenerative medicine is a rapidly expanding discipline. However due to a lack of validated outcome measures, clinical trials have been far few. This study aims to assess the validity, inter-observer reliability and intra-observer reproducibility of experimental fracture healing assessment on plain radiographies. This technique involves implantation of mesenchymal stem cell (MSC) seeded constructs on only one side of the fracture after randomisation.

The conventional Knee arthroplasty jigs, while being usually accurate, often result in prostheses being inserted in an undesired alignment resulting in poor postoperative outcome. This is especially true about unicompartmental knee replacement. Computer navigation and roboticaly assisted unicompartmental knee replacement were introduced in order to improve surgical accuracy of the femoral and tibial bone cuts.

The aim of this study was to assess accuracy and reliability of robotic assisted, unicondylar knee surgery (Makoplasty) in producing reported bony alignment. Two hundred and twenty consecutive patients who underwent medial robotic assisted unicondylar knee surgery (Makoplasty) performed by two surgeons (RJ & GP) were retrospectively identified and included in the study. Femoral and tibial sagittal and coronal alignments and posterior slope of the tibial component were measured in the post-operative radiographs. These measurements were compared with the equivalent measurements collected during intra-operative period by the navigation to study the reliability and accuracy of femoral and tibial cuts.

The aim of this study was to assess the increase in the anterior diameter of the knee and the impact of this increase on the range of motion and function of the knee.

Twenty-eight patients (34 knees) who underwent Patello-femoral replacement with FPV (Wright Medical) prosthesis between 2005 and 2009 who were identified retrospectively and analyzed using chart and radiological review. Oxford and AKSS knee-scores were gathered prospectively pre-operative and at follow-up.

Trochlear height was measured using lateral radiograph. Trochlear height was compared pre and postoperatively. Patellar height was also measured in preoperative and postoperative skyline view and was compared. The range of movement at six weeks and the Oxford and American knee society knee scores at six months postoperatively were noted. Association between increased anterior height and improved range of motion was studied.

All but three-knees regained full knee extension. Postoperative mean range of flexion of the knee joint was 116 degrees. The mean Oxford knee and the mean American Knee Society Knee Scores significantly improved post-operatively

The trochlear height was increased by 4mms. Patellar height was also increased by 3 mms resulting in average total increase of 7 mms in the anterior-posterior diameter of the knee. We found no relationship between range of motion of the knee and the increase in the anterior-posterior diameter. We found a negative correlation between increase in the antero-posterior and preoperative trochlear and patellar height.

We conclude that FPV Patello-femoral replacement results in correct anatomical reconstruction of the trochlear height rather than ‘overstuffing’ of the patellofemoral joint which can lead to stiffness and failure of resolution of pain post-operatively. This should in turn result in durable improvements in pain and function.

The conventional Knee arthroplasty jigs, while being usually accurate, often result in prostheses being inserted in an undesired alignment resulting in poor postoperative outcome. This is especially true about unicompartmental knee replacement. Computer navigation and roboticaly assisted unicompartmental knee replacement were introduced in order to improve surgical accuracy of the femoral and tibial bone cuts.

The aim of this study was to assess accuracy and reliability of robotic assisted, unicondylar knee surgery (Makoplasty) in producing reported bony alignment. Two hundred and twenty consecutive patients who underwent medial robotic assisted unicondylar knee surgery (Makoplasty) performed by two surgeons (RJ & GP) were retrospectively identified and included in the study. Femoral and tibial sagittal and coronal alignments and posterior slope of the tibial component were measured in the post-operative radiographs. These measurements were compared with the equivalent measurements collected during intra-operative period by the navigation to study the reliability and accuracy of femoral and tibial cuts.

Recently in the literature the indications of unicompartmental knee arthroplasty have been extended by the inclusion of patients with arthritis which is predominantly but not exclusively effecting the medial compartment. The aim of this study is to evaluate the outcome of MAKO unicondylar replacement in the treatment of knee osteoarthritis after the initial surgical insult is worn off to evaluate the impact of residual patellofemoral and lateral osteoarthritis on the outcome of medial unicompartmental knee replacement.

135 patients who underwent uncomplicated 144 MAKO medial unicondylar replacements for knee arthritis were identified and studied. Original radiographs were used to classify severity of patellofemoral and lateral compartmental osteoarthritis in these patients. Severity of patellofemoral and lateral compartmental osteoarthritis was analyzed against Oxford and Knee Society (AKSS) scores and amount of ipsilateral residual knee symptoms at 6 months post-operative period.

Pre-operative Oxford and Knee Society scores, and other comorbidities and long term disability were studied as confounding variables.

We found significant improvement in symptoms and scores in spite of other compartment disease. Poorer outcome was seen in association with comorbidities and long term disability but not when radiographic signs of arthritis in the other compartments were present. Six patients required revision of which three had (lateral facet) patellofemoral disease in the original x-rays.

In conclusion there is no direct relationship between postoperative symptoms and poor outcome and radiographic disease in the other compartments. However when symptoms are severe enough to necessitate revision this is due to patellofemoral and not lateral compartment disease.

Robots have been used in surgery since the late 1980s. Orthopaedic surgery began to incorporate robotic technology in 1992, with the introduction of ROBODOC, for the planning and performance of total hip replacement. The use of robotic systems has subsequently increased, with promising short-term radiological outcomes when compared with traditional orthopaedic procedures. Robotic systems can be classified into two categories: autonomous and haptic (or surgeon-guided). Passive surgery systems, which represent a third type of technology, have also been adopted recently by orthopaedic surgeons.

While autonomous systems have fallen out of favour, tactile systems with technological improvements have become widely used. Specifically, the use of tactile and passive robotic systems in unicompartmental knee replacement (UKR) has addressed some of the historical mechanisms of failure of non-robotic UKR. These systems assist with increasing the accuracy of the alignment of the components and produce more consistent ligament balance. Short-term improvements in clinical and radiological outcomes have increased the popularity of robot-assisted UKR.

Robot-assisted orthopaedic surgery has the potential for improving surgical outcomes. We discuss the different types of robotic systems available for use in orthopaedics and consider the indication, contraindications and limitations of these technologies.

The treatment of femoral non-union, especially femoral exchanged nailing, has had mixed results in the recent literature. A review of the literature has suggested that exchanged nailing may be the gold standard for the treatment of femoral non-union. Is femoral exchange nailing an acceptable method of treatment of femoral fracture non-union? What is the evidence? In this systematic review we compare four different methods for the treatment of femoral non-union.

English speaking literature from 1970 to 2007 was searched using Pubmed^® and OVID™ databases and a manual reference search to reveal the original research, presenting the results of the treatment of femoral non-union with exchange nailing, plating, external fixation, and isolated bone grafting. Outcome parameters chosen were union rate and speed of union. The baseline variables chosen were age, number of surgeries, infection and the type of non-union.

In total, fifty six case series were identified containing 861 patients treated with exchange nailing (31 studies), 214 patients treated with plating (11 studies), 140 patients treated with external fixation (13 studies), 81 patients treated with bone grafting (4 studies). The average union rate was 89% for exchange nailing, 93% for plating and external fixation and 62% for bone grafting. Speed of union was 7.3 months for exchange nailing, 8.6 months for plating and 9.15 months for external fixation.

Study of baseline variables showed patients to be older in plating and external fixation groups (range 32–44 years, P< 0.001). There were more previous operations performed in the external fixation and plating groups (3 and 1.8 vs. 1.2, P< 0.001), significantly more infected non-unions in the plating and external fixation groups as compared to the exchange nailing group (40% vs. 11.5% P< 0.001) and significantly more atrophic non-unions in the plating and external fixation groups as compared to the exchange nailing group (85% vs. 65%, P< 0.001).

The literature suggests that femoral exchange nailing has an equivalent or poorer outcomes when compared to external fixation and plating in spite of having been performed in potentially less complex cases. Plating of non-union in the literature has a higher rate of associated bone grafting than femoral exchange nailing which may be responsible for marginally better union rate in the external fixation and plating groups.

Isolated bone grafting without revision of fixation does not provide adequate union rate and hence may be of questionable treatment value.

Proximal ulnar fractures may be difficult to treat and may result in chronic instability, non-union heterotrophic ossification, synostosis, stiffness and post-traumatic arthritis. The aim of this study is to study success of treatment in achieving stable reduction and early rehabilitation.

Between December 2003 and January 2007 fifty patients (fifty-one elbows) which had sustained 21.A3 and 21.C3 fractures were identified and retrospectively studied.

There were two broad groups of patients. Young males following high energy injuries (average age=38+/−16) and old females with osteoporotic fractures (average age=65+/−17). Twenty-two patients had associated monteggia and seven patients had trans-olacrenon dislocation. Twenty-three patients had radial sided injury. This included two capitelar fractures, nineteen radial head and neck fractures and one radial shaft fracture. Fortyfive patients were treated with plating and two patients were treated with tension band wiring. Five different plating techniques were used to stabilize the fractures.

Eighteen patients had incongruent reduction. Eighteen patients had complications of the treatment. There were seven cases of non-union, one case of loss of fixation, three cases of heterotrophic ossification, three cases of synostosis, one case of deep infection and five complications resulting from radial head fractures.

There was no relationship between loss of fixation and plating techniques. There was a direct relation between comminution and post fixation incongruence. Heterotrophic ossification was associated with comminution, radial head fracture, monteggia fracture-dislocation and non-union. Radio-ulnar synostosis was associated with comminution of the ulnar fracture.

In conclusion, the main predictor of poor outcome is the comminution of proximal ulnar fracture and the ability to achieve congruous fracture fixation.

The aim of this study was to document the thickness of the patellofemoral joint before and after unicompart-mental joint replacement and to correlate these data with knee outcome scores.

Seventeen patients (22 knees) who underwent Patello-femoral replacement with FPV (Wright Medical) prosthesis between 2006 and 2008 were identified retrospectively and analyzed using chart and radiological review. Oxford and AKSS knee scores were gathered prospectively pre-operative and at follow-up.

Trochlear height was measured using lateral radiograph of the knee by measuring the distance between anterior distal femoral cortex and the highest point of trochlea. Trochlear height was compared pre and postoperatively. The range of movement and the Oxford and American knee society knee scores at six weeks postoperatively were noted. Association between increased trochlear height and improved range of motion was studied.

All but two patients regained full knee extension. Postoperative mean range of flexion of the knee joint was 114 degrees. The mean Oxford knee score at 6 weeks postoperatively was 21 points. The mean American Knee Society Knee Score was 85 points and function score 60 points.

We found the average trochlear height to be 6.2 mms pre and 9.7 mms post operatively with an average increase of 3.5 mms. We found no relationship between range of motion of the knee and knee function and trochlear height. This is important because there has been concern that ‘overstuffing’ of the patellofemoral joint can lead to stiffness and failure of resolution of pain post-operatively. Rather it appears that the FPV prosthesis restores the previous anatomical thickness of this compartment.

We conclude that FPV Patello-femoral replacement results in correct anatomical reconstruction of the trochlear height. This should in turn result in durable improvements in pain and function

Purposes of the study: Anterior cruciate ligament (ACL) deficiency is associated with degenerative osteoarthritis especially when it is present with meniscal injury; We assessed the impact of certain aetiological factors in chondral degeneration in the ACL deficient knee.

Methodology and Results: Fifty-eight patients who underwent consecutive primary arthroscopic anterior cruciate ligament reconstruction using the four strand hamstring graft between 10/06/2004 and 29/06/2006 were retrospectively analysed.

Patient’s charts and radiology findings were reviewed with special attention to operative notes and preoperative knee MR imaging. Patients with knee symptoms prior to presenting injury were excluded.

The mechanism of injury, the time elapsed from the original injury to anterior cruciate ligament reconstruction, associated meniscal injury, and quality of cartilage in the knee- at the time of MR imaging and ACL reconstruction were noted. Degenerative cartilage changes were graded upon reconstruction using the Outerbridge classification.

The average time from Injury to MR imaging and MR to ACL reconstruction was 4.85 and 12.65 months respectively.

We found a direct relationship between the time elapsed after the ACL injury and the severity of the chondral lesion (p< 0.05). Furthermore, a significant worsening in chondral degeneration of the involved knee was seen when the MR imaging and ACL reconstruction were more than 12 months apart (p< 0.01).

Conclusion: We conclude that chondral lesions and degeneration are more likely to be caused by an extended period of knee instability following ACL injury as opposed to age related degeneration or direct trauma to the weight bearing area of the knee.

Early reconstruction may protect the knee from chondral wear and subsequent degenerative arthritis.

The aim of this study is to assess the success of posterior lumbar interbody fusion in the treatment of degenerative spinal instability. Methods: Historical prospective study containing sixty-five consecutive patients who underwent posterior lumbar interbody fusion (PLIF) using carbon cages and pedicle fixation between 1993 and 2000.

Clinical outcome was assessed by the postoperative symptomatic relief, complications rate and the fusion rate. The fusion rate was assessed using plain radiographs and the Brantigan and Steffee scoring system. Functional outcome was measured by the improvement in the Oswestry disability index, PROLO score, return to work and satisfaction with the surgical outcome. The determinants of functional relief were analysed against the improvement in disability using multiple regression analysis. Results: Overall fusion rate was ninety eight percent. There was a significant improvement in Oswestry disability index P< 0.001. There was 85% satisfaction with the surgical procedure and 58% return to pre-disease activity level. We found preoperative level of disability to be best the determinant of functional recovery irrespective of age or the degree of psychological morbidity (p< 0.0001). Conclusion: The combination of posterior lumbar interbody fusion (PLIF) and posterior instrumented fusion is a safe and effective method of achieving segmental fusion with sustained functional relief and high satisfaction rate. Direct relationship between preoperative level of disability and functional recovery suggests that spinal fusion should be performed to alleviate disability caused by degenerative spine.

The management of long bone infected non-unions; posttraumatic chronic osteomyelitis and primary segmental bone defects constitute some of the most difficult reconstructive challenges encountered by orthopaedic surgeons. Measures employed to treat these conditions are tantamount to limb salvage with amputation a likely outcome if reconstructive endeavors prove unsuccessful. The Ilizarov method of distraction osteogenesis and bone transport, following radical debridement in the case of infection, is one potential management option in such cases.

Aim: To assess outcome in a cohort of patients with long bone defects treated with this technique.

Methods: Clinical review coupled with retrospective chart study and radiographic assessment.

Results: 24 patients (20 adults, 4 children) underwent treatment over a 6-year period. 21 had defects of a primary traumatic aetiology (18 tibial and 3 femoral fractures). The mean interval between injury and commencing bone transport was 41.6 months. The mean defect dimension requiring transport was 9cm (range 4.5 to 28cm). The mean external fixation time was 14.6 months. Union occurred in 21 cases. Autologous bone grafting of the docking site was performed in 6 cases in order to stimulate union. Following removal, frames were reapplied in 4 cases due to refracture or development of angular deformity. Two patients proceeded to below knee amputations. According to ASAMI* criteria, the bone result was excellent in 12 patients, good in 5 patients, fair in one patient and poor in 6 patients. Functional outcome was excellent in 7 patients, good in 12, fair in 2 and poor in 3.

Conclusion: The Ilizarov method of bone transport is a reliable procedure providing consistent results in complex cases when frequently alternative treatment options have been exhausted. Outcome compares favorably with other treatment modalities such as vascularised free tissue transfer or Papineau type grafting procedures. The treatment period is lengthy and both major and minor complications are common but limb salvage is successful in the main part. More aggressive treatment and appropriate fracture management in the early stages may have a role to play in improving the prognosis of these patients.

*Association for the Study and Application of the Methods of Ilizarov

Absorbable cement restrictors have been in use over the last few years. They have been shown to be as effective as the standard non-absorbable cement restrictors in achieving cement pressurisation and stopping distal cement migration in in vitro studies. The aim of this study is to compare in vivo, the effectiveness of absorbable with non-absorbable cement restrictors.

One hundred and thirty-six consecutive patients who had total hip replacement performed using charnley cemented femoral prosthesis were selected and randomly divided in to two groups pre operatively. One group received Hardinge TM non-absorbable cement restrictor and the second group received Biostop TM absorbable cement restrictor. Type of the prosthesis, the surgical approach, the time from start of mixing of the cement to insertion of the cement (measure of viscosity of the cement), the cementing technique and the distance at which the cement restrictor was inserted were noted intraoperatively, the canal diameter was measured from the preoperative AP radiograph of the hip. The distance at which the cement restrictor was inserted was measured on the AP radiograph of the hip taken twenty-four hours postoperatively. All the above factors were statistically assessed as to their effect in the distal migration on cement restrictor using multiple regression analysis.

There was no statistical difference between the two types of cement restrictors (P= 0.44). Surgeon, Surgical approach, femoral canal diameter P> 0.2 cementing technique P> 0.1 and Cement viscosity P= 0.082 had no effect on the degree of distal migration of the cement.

In conclusion Biostop TM absorbable cement restrictor is as effective as Hardinge TM non-absorbable cement restrictor. We could not show any relationship between femoral canal diameter cementing technique and cement viscosity and distal cement migration which leads us to conclude that in the presence of adequate cement restriction these factors have little effect in distal migration of cement mantle.

Posterior lumbar interbody fusion is a well described procedure for the treatment of back pain associated with degenerative disc disease and segmental instability. It allows decompression of the spinal canal and circumferential fusion through a single posterior incision.

Sixty-five consecutive patients who underwent posterior lumbar interbody fusion (PLIF) using carbon cages and pedicle fixation between 1993 and 2000 were recruited and contacted with a postal survey.

Clinical outcome was assessed by the assessment of postoperative clinical findings and complications and the fusion rate, which was assessed using standard X-rays with the scoring system described by Brantigan and Steffee. Functional outcome was measured by using improvement in the Oswestry Disability Index, PROLO score, return to work and satisfaction with the surgical outcome. The determinants of functional relief were analysed against the improvement in disability using multiple regression analysis.

The mean postoperative duration at the time of the study was 4.4 years. The response rate to the survey was 84%. Overall radiological fusion rate was ninety eight percent. There was a significant improvement in Oswestry Disability Index P< 0.001. There was 85% satisfaction with the surgical procedure and 58% return to pre-disease activity level and full employment. In the presence of near total union rate we found preoperative level of disability to be best the determinant of functional recovery irrespective of age or the degree of psychological morbidity (p< 0.0001).

The combination of posterior lumbar interbody fusion (PLIF) and posterior instrumented fusion is a safe and effective method of achieving circumferential segmental fusion. This procedure gives sustained long-term improvement in functional outcome and high satisfaction rate. Direct relationship between preoperative level of disability and functional recovery suggests that spinal fusion should be performed to alleviate disability caused by degenerative spine.

Assessment and referral of spinal disease in a primary care setting is a challenge for the general practitioner. This has led to establishment of spinal assessment clinic to insure prompt access to the patient who requires treatment by a spinal surgeon. These clinics are run by a trained physiotherapist who liaises with a member of the spinal team and decides the need for referral to the spinal clinic on the bases of the patient’s history and clinical examination. In our clinic each patient is also assessed with Oswestry disability index, Short form-36, visual analogue score and hospital anxiety score (HADS), although these scores do not contribute to the clinical decision-making. The aim of this study is to assess the screening value of Oswestry disability score, Short form-36 scores in diagnosing acute spinal pathology.

Sixty-nine patients who were referred to the spine clinic from the assessment clinic between March and December 2001 were recruited. Sixty-nine age and sex-matched patients were randomly chosen from five hundred and twelve patients who were seen in the spinal assessment clinic and did not need referral to the specialised spine clinic. The Oswestry disability score, Short form-36 scores and pain visual analogue scores between the two groups were statistically compared. The correlation between the level of psychological morbidity, length of symptoms and presence of past history of symptoms against the level of disability was statistically assessed.

Although there was a significant increase in the level of disability in the referred group with each score (Oswestry Disability Score P< 0.001, SF-36 physical component score P=0.014, Visual analogue pain score P< 0.001). The variation in the scores makes the scoring system unspecific for use as a screening tool. We also found strong relationship between psychological disability and length of symptoms indicating the need for prompt treatment for back pain.

Posterior lumbar interbody fusion is a well-described procedure for the treatment of back pain associated with degenerative disc disease and segmental instability. It allows decompression of the spinal canal and circumferential fusion through one posterior incision. The aim of this study is to assess fusion rate as well as long term outcome of this procedure.

Methods: Fifty-six consecutive patients who underwent posterior lumbar interbody fusion (PLIF) using carbon cages and pedicle fixation between 1993 and 2000 were recruited and contacted with postal survey. Clinical outcome was measured using changes in Oswestry Disability Index (before the surgery and at the time of the study) and patient questionnaire containing pain improvement, analgesic use, return to work and satisfaction with surgical outcome.

Fusion rate was assessed using standard X-rays with scoring system described by Brantigan and Steffee.

Results: The average age of the patients at the time of surgery was 43 years. The complication involved one misplaced pedicle screw, one dural tear, one deep infection, one displacement of the cage and one pulmonary embolism. The mean postoperative duration at the time of the study was 4.4 years. The response rate to the survey was 84%. Overall radiological fusion rate was 94%. There was a significant improvement in Oswestry Disability Index P< 0.001. Eighty five percent of the patients were satisfied with their surgical outcome and fifty eight percent of the work eligible patients had resumed their pre-disease activity level and full employment.

Conclusions: The combination of posterior lumbar inter-body fusion (PLIF) with posterolateral instrumented fusion is a safe and effective method of achieving circumferential segmental fusion. This procedure gives sustained long-term improvement in functional outcome and high satisfaction rate.